Google has filed a patent application for a wearable device that can test diabetics' blood sugar levels without the use of a needle.

The application, filed with the U.S. Patent & Trademark Office on Dec. 3, is for a wrist-worn device that uses pressurized gas to pierce the user's skin and draw in a "micro-emergence" of blood to be tested.

The device might not be for diabetics alone. The patent application notes that blood could be tested for various qualities, including hormone levels, proteins and enzymes, which could factor into various medical conditions.

Diabetics typically use a small needle, called a lancet, to pierce the skin and extract a droplet of blood, which is then tested using a glucose meter. The test is usually done on a finger. The smaller the lancet, the less painful the procedure is for the patient.

As lancets have become thinner, however, they are more apt to bend or break and not properly pierce the skin.

Since diabetics generally test their glucose levels at least once a day, if not two to four times, the finger sticks become painful, discouraging the patient from doing the tests as often as they should.

Unchecked, and hence unbalanced, blood glucose levels could lead to blindness and nerve damage, as well as heart and kidney damage.

That's why Google is working with pressurized gas to make tiny openings in the skin, decreasing the pain and inconvenience of traditional finger sticks.

According to the patent application, the pressurized gas is able to "imperceptibly pierce dermal tissue without a piercing element."

Google did not respond to a request for comment on the patent application.

This isn't Google's first foray into creating testing devices for diabetics. Nearly a year ago, reports surfaced that the company was in talks with the U.S. Food and Drug Administration to create a smart contact lens that would use sensors, chips, and antennas to test diabetics' blood sugar levels.

The lens, which was designed to test the blood sugar level in the user's tears, was in a prototype stage at the time.

Last year, the company said that its scientists were looking into lenses that also offering a warning to users when their blood sugar levels were too high or too low. A tiny LED light in the lens could be triggered to serve as a warning, for example.